| alpha-d-glucuronidases from the xylanolytic thermophiles clostridium stercorarium and thermoanaerobacterium saccharolyticum. | alpha-d-glucuronidases were purified from the xylanolytic thermophiles clostridium stercorarium and thermoanaerobacterium saccharolyticum. this enzyme activity was found to be intracellular in each organism, with t. saccharolyticum producing much greater total activity. the specific activities of the purified enzymes (10 u mg-1 t. saccharolyticum; 1.7 u mg-1 c. stercorarium) differed by a factor of approximately 5. for the determination of enzyme activities, 4-o-methyl-alpha-d-glucuronosyl-xylot ... | 1995 | 7496513 |
| synthesis of heat shock proteins in thermoanaerobacterium thermosulfurigenes em1 (clostridium thermosulfurogenes em1). | the response to heat stress was examined in thermoanaerobacterium thermosulfurigenes em1. upon a temperature shift-up from 50 degrees to 62 degrees c, four heat shock proteins (hsps) were synthesized at an elevated level. two proteins were found to be immunologically related to the escherichia coli groel protein and the mycobacterium tuberculosis hsp71 (dnak similar protein), and the corresponding groe and dnak homologous sequences were detected in the chromosome of t. thermosulfurigenes em1. th ... | 1994 | 7517249 |
| purification and characterization of two thermostable acetyl xylan esterases from thermoanaerobacterium sp. strain jw/sl-ys485. | two acetyl esterases (ec 3.1.1.6) were purified to gel electrophoretic homogeneity from thermoanaerobacterium sp. strain jw/sl-ys485, an anaerobic, thermophilic endospore former which is able to utilize various substituted xylans for growth. both enzymes released acetic acid from chemically acetylated larch xylan. acetyl xylan esterases i and ii had molecular masses of 195 and 106 kda, respectively, with subunits of 32 kda (esterase i) and 26 kda (esterase ii). the isoelectric points were 4.2 an ... | 1995 | 7574610 |
| phylogenetic analysis of anaerobic thermophilic bacteria: aid for their reclassification. | small subunit rdna sequences were determined for 20 species of the genera acetogenium, clostridium, thermoanaerobacter, thermoanaerobacterium, thermoanaerobium, and thermobacteroides, 3 non-validly described species, and 5 isolates of anaerobic thermophilic bacteria, providing a basis for a phylogenetic analysis of these organisms. several species contain a version of the molecule significantly longer than that of escherichia coli because of the presence of inserts. on the basis of normal evolut ... | 1993 | 7687600 |
| evidence for a general role for non-catalytic thermostabilizing domains in xylanases from thermophilic bacteria. | a genomic library of clostridium thermocellum dna constructed in lambda zapii was screened for xylanase-expressing clones. cross-hybridization experiments revealed a new xylanase gene isolated from the gene library, which was designated xyn y. the encoded enzyme, xylanase y (xyly), displayed features characteristic of an endo-beta1,4-xylanase: the enzyme rapidly hydrolysed oat spelt, wheat and rye arabinoxylans and was active against methyl-umbelliferyl-beta-d-cellobioside, but did not hydrolyse ... | 1995 | 7717969 |
| cyclodextrin formation by the thermostable alpha-amylase of thermoanaerobacterium thermosulfurigenes em1 and reclassification of the enzyme as a cyclodextrin glycosyltransferase. | extensive characterization of the thermostable alpha-amylase of clostridium thermosulfurogenes em1, recently reclassified as thermoanaerobacterium thermosulfurigenes, clearly demonstrated that the enzyme is a cyclodextrin glycosyltransferase (cgtase). product analysis after incubation of the enzyme with starch revealed formation of alpha-, beta-, and gamma-cyclodextrins, as well as linear sugars. the specific activity for cyclization of this cgtase was similar to those of other cgtases, whereas ... | 1995 | 7747949 |
| crystallization and preliminary x-ray diffraction studies of xylose isomerase from thermoanaerobacterium thermosulfurigenes strain 4b. | xylose isomerase from the thermophile thermoanaerobacterium thermosulfurigenes strain 4b has been crystallized by vapour diffusion from jeffamine ed 4000 as precipitant. the crystal symmetry is p2(1)2(1)2(1), with unit cell dimensions a = 85.6 a, b = 153.5 a and c = 158.5 a. the protein molecular mass and volume of the unit cell is consistent with the presence of a tetramer of the enzyme in the asymmetric unit. the crystals diffract x-rays from a synchrotron source to 1.7 a resolution. | 1994 | 8046754 |
| cloning and sequencing of the thermoanaerobacterium saccharolyticum b6a-ri apu gene and purification and characterization of the amylopullulanase from escherichia coli. | the amylopullulanase gene (apu) of the thermophilic anaerobic bacterium thermoanaerobacterium saccharolyticum b6a-ri was cloned into escherichia coli. the complete nucleotide sequence of the gene was determined. it encoded a protein consisting of 1,288 amino acids with a signal peptide of 35 amino acids. the enzyme purified from e. coli was a monomer with an m(r) of 142,000 +/- 2,000 and had same the catalytic and thermal characteristics as the native glycoprotein from t. saccharolyticum b6a. li ... | 1994 | 8117096 |
| the xylose isomerase-encoding gene (xyla) of clostridium thermosaccharolyticum: cloning, sequencing and phylogeny of xyla enzymes. | the xylose isomerase (xyla)-encoding gene (xyla) of the thermophilic anaerobic bacterium, clostridium thermosaccharolyticum ncib 9385, was cloned as a 4.0-kb dna fragment by complementation of the escherichia coli xyla mutant strain, ds941. the open reading frame of 1317 bp encoded a protein of 439 amino acids (aa), with a calculated m(r) of 50,236. the gene was preceeded by a typical clostridial shine-dalgarno sequence, and was expressed constitutively in the cloning host. downstream, the clone ... | 1994 | 8163183 |
| pullulanase of thermoanaerobacterium thermosulfurigenes em1 (clostridium thermosulfurogenes): molecular analysis of the gene, composite structure of the enzyme, and a common model for its attachment to the cell surface. | the complete pullulanase gene (amyb) from thermoanaerobacterium thermosulfurigenes em1 was cloned in escherichia coli, and the nucleotide sequence was determined. the reading frame of amyb consisted of 5,586 bp encoding an exceptionally large enzyme of 205,991 da. sequence analysis revealed a composite structure of the pullulanase consisting of catalytic and noncatalytic domains. the n-terminal half of the protein contained a leader peptide of 35 amino acid residues and the catalytic domain, whi ... | 1994 | 8195085 |
| gene cloning, sequencing, and biochemical characterization of endoxylanase from thermoanaerobacterium saccharolyticum b6a-ri. | the gene encoding endoxylanase (xyna) from thermoanaerobacterium saccharolyticum b6a-ri was cloned and expressed in escherichia coli. a putative 33-amino-acid signal peptide, which corresponded to the n-terminal amino acids, was encoded by xyna. an open reading frame of 3,471 bp, corresponding to 1,157 amino acid residues, was found, giving the xyna gene product a molecular mass of 130 kda. xyna from t. saccharolyticum b6a-ri had strong similarity to genes from family f beta-glycanases. the temp ... | 1993 | 8215382 |
| cloning, sequencing and biochemical characterization of xylose isomerase from thermoanaerobacterium saccharolyticum strain b6a-ri. | the xylose isomerase gene from thermoanaerobacterium saccharolyticum strain b6a-ri was cloned by complementation using escherichia coli xyl-5 mutant strain hb101. one positive clone was detected and the recombinant plasmid, pzx16, was isolated. the clone contained the vector puc18 and an insert fragment of 4.5 kb. the cloned xylose isomerase gene (xyla) was expressed constitutively in e. coli. the gene contained one open reading frame (orf) of 1317 bp, which corresponds to 439 amino acid residue ... | 1993 | 8360616 |
| genetic organization, sequence and biochemical characterization of recombinant beta-xylosidase from thermoanaerobacterium saccharolyticum strain b6a-ri. | endoxylanase (xyna) and beta-xylosidase (xynb) genes from thermoanerobacterium saccharolyticum were subcloned from a cosmid clone (pxdm1) to generate pxph3. the nucleotide sequence of a psti-hindiii fragment in pxph3 that contained xynb revealed an open reading frame (orf) of 1500 bp encoding a 55 kda protein. another open reading frame (orf1) of unknown function was found 21 bp downstream from the first stop codon of xynb. xynb, orf1 and xyna had the same direction of transcription. xynb from t ... | 1993 | 8360617 |
| characterization of the active site and thermostability regions of endoxylanase from thermoanaerobacterium saccharolyticum b6a-ri. | deletion mutants were constructed from pzep12, which contained the intact thermoanaerobacterium saccharolyticum endoxylanase gene (xyna). deletion of 1.75 kb from the n-terminal end of xyna resulted in a mutant enzyme that retained activity but lost thermostability. deletion of 1.05 kb from the c terminus did not alter thermostability or activity. the deduced amino acid sequence of t. saccharolyticum b6a-ri endoxylanase xyna was aligned with five other family f beta-glycanases by using the pileu ... | 1993 | 8376336 |
| the role of active-site aromatic and polar residues in catalysis and substrate discrimination by xylose isomerase. | the functions of individual amino acid residues in the active site of thermoanaerobacterium thermosulfurigenes d-xylose ketol-isomerase (ec 5.3.1.5) were studied by site-directed substitution. the role of aromatic residues in the active-site pocket was not limited to the creation of a hydrophobic environment. for example, trp-188 provided for substrate binding and trp-139 allowed for the discrimination between d-xylose and d-glucose. substrate discrimination was accomplished by steric hindrance ... | 1993 | 8378319 |
| molecular analysis of the amy gene locus of thermoanaerobacterium thermosulfurigenes em1 encoding starch-degrading enzymes and a binding protein-dependent maltose transport system. | a gene of thermoanaerobacterium thermosulfurigenes em1 encoding a protein with similarity to the maltose-binding protein of escherichia coli was cloned and sequenced. it was located in the amy gene region of the chromosome downstream of the pullulanase-encoding amyb gene and upstream of amydc, encoding membrane components of an abc transport system, and the alpha-amylase gene amya. the gene was designated amye. analysis of mrna by northern (rna) blotting revealed that expression of the amy gene ... | 1996 | 8576036 |
| crystal structure at 2.3 a resolution and revised nucleotide sequence of the thermostable cyclodextrin glycosyltransferase from thermonanaerobacterium thermosulfurigenes em1. | the crystal structure of the cyclodextrin glycosyltransferase (cgtase) from the thermophilic microorganism thermoanaerobacterium thermosulfurigenes em1 has been elucidated at 2.3 a resolution. the final model consists of all 683 amino acid residues, two calcium ions and 343 water molecules, and has a crystallographic r-factor of 17.9% (rfree 24.9%) with excellent stereochemistry. the overall fold of the enzyme is highly similar to that reported for mesophilic cgtases and differences are observed ... | 1996 | 8604143 |
| stereochemical course and reaction products of the action of beta-xylosidase from thermoanaerobacterium saccharolyticum strain b6a-ri. | beta-xylosidases are grouped in families 39 and 43 of a general classification of glycosyl hydrolases based on amino acid sequence similarities. the beta-xylosidase from butyrivibrio fibrisolvens, which belongs to family 43, has been shown to operate by a molecular mechanism which results in the inversion of the anomeric configuration. thermoanaerobacterium saccharolyticum b6a-ri beta-xylosidase which belongs to family 39 was purified as a recombinant enzyme from escherichia coli. the stereochem ... | 1996 | 8612648 |
| cloning, sequencing, and expression of the gene encoding a large s-layer-associated endoxylanase from thermoanaerobacterium sp. strain jw/sl-ys 485 in escherichia coli. | the gene (xyna) encoding a surface-exposed, s-layer-associated endoxylanase from thermoanaerobacterium sp. strain jw/sl-ys 485 was cloned and expressed in escherichia coli. a 3.8-kb fragment was amplified from chromosomal dna by using primers directed against conserved sequences of endoxylanases isolated from other thermophilic bacteria. this pcr product was used as a probe in southern hybridizations to identify a 4.6-kb ecori fragment containing the complete xyna gene. this fragment was cloned ... | 1996 | 8626279 |
| purification and cloning of a thermostable xylose (glucose) isomerase with an acidic ph optimum from thermoanaerobacterium strain jw/sl-ys 489. | an unusual xylose isomerase produced by thermoanaerobacterium strain jw/sl-ys 489 was purified 28-fold to gel electrophoretic homogeneity, and the biochemical properties were determined. its ph optimum distinguishes this enzyme from all other previously described xylose isomerases. the purified enzyme had maximal activity at ph 6.4 (60 degrees c) or ph 6.8 (80 degrees c) in a 30-min assay, an isoelectric point at 4.7, and an estimated native molecular mass of 200 kda, with four identical subunit ... | 1996 | 8830690 |
| characterization of genes from thermoanaerobacterium thermosulfurigenes em1 that encode two glycosyl hydrolases with conserved s-layer-like domains. | two genes from thermoanaerobacterium thermosulfurigenes em1 were identified which are predicted to encode a xylanase (xyna) and a polygalacturonate hydrolase (pg1a). the xyna gene has the potential to encode a 1234-amino acid product consisting of a signal peptide followed by a repeated domain, a xylanase family f domain, two cellulose-binding domains and a triplicated sequence at its c-terminus. the gene pgla is predicted to encode a product of 1148 amino acids consisting of a signal sequence f ... | 1996 | 8879252 |
| quaternary structure, mg2+ interactions, and some kinetic properties of the beta-galactosidase from thermoanaerobacterium thermosulfurigenes em1. | the beta-galactosidase from thermoanaerobacterium thermosulfurigenes em1 was found to be a dimer with a monomer molecular weight of about 85,000. it lacks the alpha-peptide and an important alpha-helix that are both needed for dimer-dimer interaction and there is no homology in other important dimer-dimer interaction areas. these differences in structure probably account for the dimeric (rather than tetrameric) structure. only 0.19 mg2+ bound per monomer and mg2+ had only small effects on the ac ... | 1996 | 8968953 |
| isolation and characterization of an amino sugar-rich glycopeptide from the surface layer glycoprotein of thermoanaerobacterium thermosaccharolyticum e207-71. | | 1996 | 9002194 |
| functions of s-layers. | although s-layers are being increasingly identified on bacteria and archaea, it is enigmatic that in most cases s-layer function continues to elude us. in a few instances, s-layers have been shown to be virulence factors on pathogens (e.g. campylobacter fetus ssp. fetus and aeromonas salmonicida), protective against bdellovibrio, a depository for surface-exposed enzymes (e.g. bacillus stearothermophilus), shape-determining agents (e.g. thermoproteus tenax) and nucleation factors for fine-grain m ... | 1997 | 9276929 |
| isolation, analysis, and expression of two genes from thermoanaerobacterium sp. strain jw/sl ys485: a beta-xylosidase and a novel acetyl xylan esterase with cephalosporin c deacetylase activity. | the genes encoding acetyl xylan esterase 1 (axe1) and a beta-xylosidase (xylb) have been cloned and sequenced from thermoanaerobacterium sp. strain jw/sl ys485. axe1 is located 22 nucleotides 3' of the xylb sequence. the identity of axe1 was confirmed by comparison of the deduced amino acid sequence to peptide sequence analysis data from purified acetyl xylan esterase 1. the xylb gene was identified by expression cloning and by sequence homology to known beta-xylosidases. plasmids which independ ... | 1997 | 9286998 |
| molecular characterization of genes encoding a novel abc transporter in thermoanaerobacterium thermosulfurigenes em1. | the nucleotide sequence of two open reading frames (orfs) from thermoanaerobacterium thermosulfurigenes em1 was determined that encode proteins with similarity to components of atp-binding cassette (abc) transport systems. sequence analysis suggests that the deduced proteins abca and abcb consist of an nh2-terminal membrane-spanning domain and a cooh-terminal atp-binding domain. the deduced proteins abca and abcb showed highest similarity to proteins of the msba subfamily of abc transporters. ab ... | 1997 | 9290065 |
| engineering of cyclodextrin product specificity and ph optima of the thermostable cyclodextrin glycosyltransferase from thermoanaerobacterium thermosulfurigenes em1. | the product specificity and ph optimum of the thermostable cyclodextrin glycosyltransferase (cgtase) from thermoanaerobacterium thermosulfurigenes em1 was engineered using a combination of x-ray crystallography and site-directed mutagenesis. previously, a crystal soaking experiment with the bacillus circulans strain 251 beta-cgtase had revealed a maltononaose inhibitor bound to the enzyme in an extended conformation. an identical experiment with the cgtase from t. thermosulfurigenes em1 resulted ... | 1998 | 9488711 |
| metabolic engineering of propanediol pathways. | microbial fermentation is an important technology for the conversion of renewable resources to chemicals. in this paper, we describe the application of metabolic engineering for the development of two new fermentation processes: the microbial conversion of sugars to 1,3-propanediol (1,3-pd) and 1,2-propanediol (1,2-pd). a variety of naturally occurring organisms ferment glycerol to 1,3-pd, but no natural organisms ferment sugars directly to 1,3-pd. we first describe the fed-batch fermentation of ... | 1998 | 9496676 |
| purification and properties of an amylopullulanase, a glucoamylase, and an alpha-glucosidase in the amylolytic enzyme system of thermoanaerobacterium thermosaccharolyticum. | thermoanaerobic bacteria are of considerable interest as producers of thermostable amylolytic enzymes. the soluble amylolytic enzyme system of thermoanaerobacterium thermosaccharolyticum dsm 571 was fractionated into a pullulanase, a glucoamylase, and an alpha-glucosidase. the enzymes were purified to homogeneity and their physical and catalytic properties were studied. the pullulanase, which cleaved both alpha-1,4- and alpha-1,6-glucosidic bonds, was an amylopullulanase closely related to simil ... | 1998 | 9532787 |
| the xylose isomerase gene from thermoanaerobacterium thermosulfurogenes allows effective selection of transgenic plant cells using d-xylose as the selection agent. | the xylose isomerase gene (xyla) from thermoanaerobacterium thermosulfurogenes (formerly clostridium thermosulfurogenes) has been expressed in three plant species (potato, tobacco, and tomato) and transgenic plants have been selected on xylose-containing medium. the xylose isomerase gene was transferred to the target plant by agrobacterium-mediated transformation. the xylose isomerase gene was expressed using the enhanced cauliflower mosaic virus (camv) 35s promoter and the omega' translation en ... | 1998 | 9617801 |
| engineering of factors determining alpha-amylase and cyclodextrin glycosyltransferase specificity in the cyclodextrin glycosyltransferase from thermoanaerobacterium thermosulfurigenes em1. | the starch-degrading enzymes alpha-amylase and cyclodextrin glycosyltransferase (cgtase) are functionally and structurally closely related, with cgtases containing two additional domains (called d and e) compared to the three domains of alpha-amylases (a, b and c). amino acid residue 196 (thermoanaerobacterium thermosulfurigenes em1 cgtase numbering) occupies a dominant position in the active-site cleft. all alpha-amylases studied have a small residue at this position (gly, leu, ser, thr or val) ... | 1998 | 9654055 |
| immunoelectron microscopic studies indicate the existence of a cell shape preserving cytoskeleton in prokaryotes. | immunoelectron microscopic studies of prokaryotes were performed with anti-actin antibodies directed against the c terminus of actin. studies on ultrathin sections revealed high proportions of the overall label close to the cell periphery in escherichia coli, ralstonia eutropha, thermoanaerobacterium thermosulfurigenes, t. thermosaccharolyticum, and methanococcus jannaschii. substantial label also in the cytoplasm was observed in bacillus sp., methanococcus voltae, and methanobacterium thermoaut ... | 1998 | 9686396 |
| identification of glu-277 as the catalytic nucleophile of thermoanaerobacterium saccharolyticum beta-xylosidase using electrospray ms. | thermoanaerobacterium saccharolyticum beta-xylosidase is a member of family 39 of the glycosyl hydrolases. this grouping comprises both retaining beta-d-xylosidases and alpha-l-iduronidases. t. saccharolyticum beta-xylosidase catalyses the hydrolysis of short xylo-oligosaccharides into free xylose via a covalent xylosyl-enzyme intermediate. incubation of t. saccharolyticum beta-xylosidase with 2,4-dinitrophenyl 2-deoxy-2-fluoro-beta-d-xyloside resulted in time-dependent inactivation of the enzym ... | 1998 | 9761746 |
| molecular cloning, sequencing, and expression of a novel multidomain mannanase gene from thermoanaerobacterium polysaccharolyticum. | the mana gene of thermoanaerobacterium polysaccharolyticum was cloned in escherichia coli. the open reading frame of mana is composed of 3,291 bases and codes for a preprotein of 1,097 amino acids with an estimated molecular mass of 119,627 da. the start codon is preceded by a strong putative ribosome binding site (taaggcggtg) and a putative -35 (ttcgc) and -10 (taaaat) promoter sequence. the mana of t. polysaccharolyticum is a modular protein. sequence comparison and biochemical analyses demons ... | 1999 | 10049399 |
| cell wall of thermoanaerobacterium thermosulfurigenes em1: isolation of its components and attachment of the xylanase xyna. | thermoanaerobacterium thermosulfurigenes em1 has a gram-positive type cell wall completely covered by a surface layer (s-layer) with hexagonal lattice symmetry. the components of the cell envelope were isolated, and the s-layer protein was purified and characterized. s-layer monomers assembled in vitro into sheets with the same hexagonal symmetry as in vivo. monosaccharide analysis revealed that the s-layer is associated with fucose, rhamnose, mannosamine, glucosamine, galactose, and glucose. th ... | 1999 | 10201095 |
| family 10 and 11 xylanase genes from caldicellulosiruptor sp. strain rt69b.1. | three family 10 xylanase genes (xyna, xynb, and xync) and a single family 11 xylanase gene (xynd) were identified from the extreme thermophile caldicellulosiruptor strain rt69b.1 through the use of consensus pcr in conjunction with sequencing and polyacrylamide gel electrophoresis. these genes appear to comprise the complete endoxylanase system of rt69b.1. the xyna gene was found to be homologous to the xyna gene of the closely related caldicellulosiruptor strain rt8b.4, and primers designed pre ... | 1999 | 10356996 |
| in thermoanaerobacterium thermosulfurigenes em1 s-layer homology domains do not attach to peptidoglycan. | three exocellular enzymes of thermoanaerobacterium thermosulfurigenes em1 possess a c-terminal triplicated sequence related to a domain of bacterial cell surface proteins (s-layer proteins). at least one copy of this sequence, named the slh (for s-layer homology) domain, is also present at the n terminus of the s-layer protein of this bacterium. the hypothesis that slh domains serve to anchor proteins to the cell surface was investigated by using the slh domain-containing xylanase. this enzyme w ... | 1999 | 10438774 |
| development and characterization of a gene expression reporter system for clostridium acetobutylicum atcc 824. | a gene expression reporter system (pht3) for clostridium acetobutylicum atcc 824 was developed by using the lacz gene from thermoanaerobacterium thermosulfurogenes em1 as the reporter gene. in order to test the reporter system, promoters of three key metabolic pathway genes, ptb (coding for phosphotransbutyrylase), thl (coding for thiolase), and adc (coding for acetoacetate decarboxylase), were cloned upstream of the reporter gene in pht3 in order to construct vectors pht4, pht5, and phta, respe ... | 1999 | 10473377 |
| molecular determinants of xylose isomerase thermal stability and activity: analysis of thermozymes by site-directed mutagenesis. | xylose isomerases (xis) from thermoanaerobacterium thermosulfurigenes (ttxi) and thermotoga neapolitana (tnxi) are 70.4% identical in their amino acid sequences and have a nearly superimposable crystal structure. nonetheless, tnxi is much more thermostable than ttxi. except for a few additional prolines and fewer asn and gln residues in tnxi, no other obvious differences in the enzyme structures can explain the differences in their stabilities. tnxi has two additional prolines in the phe59 loop ... | 2000 | 10810157 |
| the acetyl xylan esterase of bacillus pumilus belongs to a family of esterases with broad substrate specificity. | the bacillus pumilus gene encoding acetyl xylan esterase (axe) was identified and characterized. the axe gene was expressed and the recombinant enzyme produced in escherichia coli was purified and characterized. the recombinant enzyme displayed similar properties to the acetyl xylan esterase (axe) purified from b. pumilus. the axe primary structure was 76% identical to the cephalosporin c deacetylase of b. subtilis, and 40% to two recently identified axes from thermoanaerobacterium and thermotog ... | 2000 | 10878123 |
| a novel type of carbohydrate-protein linkage region in the tyrosine-bound s-layer glycan of thermoanaerobacterium thermosaccharolyticum d120-70. | the surface-layer (s-layer) protein of thermoanaerobacterium thermosaccharolyticum d120-70 contains glycosidically linked glycan chains with the repeating unit structure -->4)[alpha-d-galp-(1-->2)]-alpha-l-rhap-(1-->3)[beta-d-glcp-(1--> 6)] -beta-d-manp-(1-->4)-alpha-l-rhap-(1-->3)-alpha-d-glcp-(1--> . after proteolytic degradation of the s-layer glycoprotein, three glycopeptide pools were isolated, which were analyzed for their carbohydrate and amino-acid compositions. in all three pools, tyros ... | 2000 | 10951207 |
| advances in development of a genetic system for thermoanaerobacterium spp.: expression of genes encoding hydrolytic enzymes, development of a second shuttle vector, and integration of genes into the chromosome. | despite recent success in transforming various thermophilic gram-type-positive anaerobes with plasmid dna, use of shuttle vectors for the expression of genes other than antibiotic resistance markers has not previously been described. we constructed new vectors in order to express heterologous hydrolytic enzymes in our model system, thermoanaerobacterium saccharolyticum jw/sl-ys485. transformed thermoanaerobacterium expressed active enzyme, indicating that this system may function as an alternate ... | 2000 | 11055929 |
| conversion of sugars to 1,2-propanediol by thermoanaerobacterium thermosaccharolyticum hg-8. | the purpose of this study was to explore a fermentation route for the production of 1,2-propanediol (1,2-pd) from renewable sugars: lactose found in cheese whey, and d-glucose, d-galactose, l-arabinose, and d-xylose found in corn and wood byproducts. thermoanaerobacterium thermosaccharolyticum, a naturally occurring organism, was found to ferment a wider range of sugars to 1,2-pd than previously reported. the specific sugar had a significant effect on the selectivity for 1,2-pd vs other fermenta ... | 2001 | 11170479 |
| characterization of two novel saccharolytic, anaerobic thermophiles, thermoanaerobacterium polysaccharolyticum sp. nov. and thermoanaerobacterium zeae sp. nov., and emendation of the genus thermoanaerobacterium. | two anaerobic, thermophilic, gram-positive, non-spore forming bacteria with an array of polysaccharide-degrading enzymes were isolated from the leachate of a waste pile from a canning factory in hoopeston, east central illinois, usa. the results of 16s rdna sequence homology indicated that their closest relatives belong to the saccharolytic, thermophilic and anaerobic genera of thermoanaerobacterium and thermoanaerobacter. although, the evolutionary distances between these bacteria and their clo ... | 2001 | 11321073 |
| polyamines of the thermophilic eubacteria belonging to the genera thermosipho, thermaerobacter and caldicellulosiruptor. | cellular polyamines of four new thermophiles located in three early branched eubacterial clades, were investigated for the chemotaxonomic significance of polyamine distribution profiles. the thermophilic anaerobic thermosipho japonicus, belonging to the order thermotogales, contained norspermidine, norspermine and thermospermine in addition to spermidine and spermine. the polyamine profile was identical to the polyamine composition of thermotoga, fervidobacterium and petrotoga species of the ord ... | 2001 | 11327112 |
| crystallization and preliminary x-ray studies of trp138phe/val185thr xylose isomerases from thermotoga neapolitana and thermoanaerobacterium thermosulfurigenes. | xylose isomerases from thermotoga neapolitana (tnxi) and thermoanaerobacterium thermosulfurigenes (ttxi) share 70.4% sequence identity and are thermostable. the double mutants trp138phe/val185thr of tnxi and ttxi have higher catalytic efficiencies than tnxi and ttxi, respectively. the trp138phe/val185thr tnxi and ttxi mutants were overexpressed in escherichia coli strain bl21(de3) and purified. crystals of the two proteins were grown with polyethylene glycol 8000 as the major precipitant by the ... | 2001 | 11679745 |
| microbial community in anaerobic hydrogen-producing microflora enriched from sludge compost. | hydrogen production by thermophilic anaerobic microflora enriched from sludge compost was studied by using an artificial medium containing cellulose powder. hydrogen gas was evolved with the formation of acetate, ethanol, and butyrate by decomposition of the cellulose powder. the hydrogen production yield was 2.0 mol/mol-hexose by either batch or chemostat cultivation. a medium that did not contain peptone demonstrated a lower hydrogen production yield of 1.0 mol/mol-hexose with less formation o ... | 2001 | 11762604 |
| crystallization and preliminary x-ray crystallographic analysis of beta-xylosidase from thermoanaerobacterium saccharolyticum, a thermophilic anaerobe. | beta-xylosidases are involved in the breakdown of xylans into xylose and belong to either family 39 or 43 of the glycosyl hydrolases. at present, no structural information is available for any member of these families. beta-xylosidase from the thermophilic anaerobe thermoanaerobacterium saccharolyticum, a member of glycosyl hydrolase family 39, has been crystallized at 296 k using the hanging-drop vapour-diffusion method. the crystal diffracts to 2.4 a resolution with synchrotron x-rays and belo ... | 2002 | 11856846 |
| [replication protein repn encoded by the rc plasmid of thermophilic bacterium thermoanaerobacterium saccharolyticum: mutational analysis and deletion mapping of domains responsible for its lethal effect]. | amino acid sequence analysis of the product encoded by repn of thermoanaerobacterium saccharolyticum (clostridium thermosaccharolyticum) pnb2, which is capable of rolling-circle (rc) replication, revealed all known motifs conserved among replication (rep) proteins that initiate rc replication of plasmids related to pc194/pub110. using the t7 expression system in escherichia coli, repn was identified as a 35k protein. its lethal effect on bacterial cells was unusually high for a protein of the ki ... | 2002 | 11862700 |
| control of butanol formation in clostridium acetobutylicum by transcriptional activation. | the sol operon of clostridium acetobutylicum is the essential transcription unit for formation of the solvents butanol and acetone. the recent proposal that transcriptional regulation of this operon is controlled by the repressor orf5/solr (r. v. nair, e. m. green, d. e. watson, g. n. bennett, and e. t. papoutsakis, j. bacteriol. 181:319-330, 1999) was found to be incorrect. instead, regulation depends on activation, most probably by the multivalent transcription factor spo0a. the operon is tran ... | 2002 | 11889105 |
| mutations converting cyclodextrin glycosyltransferase from a transglycosylase into a starch hydrolase. | cyclodextrin glycosyltransferase (cgtase) efficiently catalyzes transglycosylation of oligo-maltodextrins, although the enzyme also has a low hydrolytic activity. its +2 substrate binding subsite, which contains the conserved phe184 and phe260 residues, has been shown to be important for this transglycosylation activity [nakamura et al. (1994) biochemistry 33, 9929-9936]. here we show that the amino acid side chain at position 260 also controls the hydrolytic activity of cgtase. three phe260 mut ... | 2002 | 11943149 |
| molecular characterization and utilization of the cak1 filamentous viruslike particle derived from clostridium beijerinckii. | an examination of the replication origin and stability determinant associated with the cak1 filamentous viruslike particle recovered from clostridium beijerinckii ncimb 6444 was carried out. seven deletion derivatives, pcke, pcep1, pdt5, pckp, pdth102, pyl102e and pyl102, were constructed and transformed into c. beijerinckii ncimb 8052. the successful transformation of pcke, pdt5, pckp, pdth102, pyl102e and pyl102 into c. beijerinckii 8052, together with the corresponding recovery of single-stra ... | 2002 | 12074052 |
| mechanism of thermoanaerobacterium saccharolyticum beta-xylosidase: kinetic studies. | the catalytic mechanism of thermoanaerobacterium saccharolyticum beta-xylosidase (xynb) from family 39 of glycoside hydrolases has been subjected to a detailed kinetic investigation using a range of substrates. the enzyme exhibits a bell-shaped ph dependence of k(cat)/k(m), reflecting apparent pk(a) values of 4.1 and 6.8. the k(cat) and k(cat)/k(m) values for a series of aryl xylosides have been measured and used to construct two brønsted plots. the plot of log(k(cat)/k(m)) against the pk(a) of ... | 2002 | 12146938 |
| a case for reverse protonation: identification of glu160 as an acid/base catalyst in thermoanaerobacterium saccharolyticum beta-xylosidase and detailed kinetic analysis of a site-directed mutant. | the catalytic mechanism of the family 39 thermoanaerobacterium saccharolyticum beta-xylosidase (xynb) involves a two-step double-displacement mechanism in which a covalent alpha-xylosyl-enzyme intermediate is formed with assistance from a general acid and then hydrolyzed with assistance from a general base. incubation of recombinant xynb with the newly synthesized active site-directed inhibitor, n-bromoacetyl-beta-d-xylopyranosylamine, resulted in rapid, time-dependent inactivation of the enzyme ... | 2002 | 12146939 |
| purification and characterization of a thermostable alpha-galactosidase from thermoanaerobacterium polysaccharolyticum. | food ingredients containing alpha-1,6-galactoside bonds elicit gastrointestinal disturbances in monogastric animals, including humans. pretreatment of such ingredients with alpha-galactosidase (ec 3.2.1.22) has the potential to alleviate this condition. for this purpose, a thermostable alpha-galactosidase from thermoanaerobacterium polysaccharolyticum was purified by a combination of anion exchange and size exclusion chromatographies. the enzyme has a monomeric molecular weight of approximately ... | 2002 | 12236697 |
| isolation of a new thermoanaerobacterium thermosaccharolyticum strain (fh1) producing a thermostable dextranase. | a gram-positive spore-forming thermophilic strict anaerobic bacterium, designated fh1, was isolated from enrichments at 65 degrees c with dextran as sole carbon and energy source. a sequence analysis of the 16s rrna gene revealed 99.2% identity of fh1 to thermoanaerobacterium thermosaccharolyticum. furthermore, the substrate spectra of both organisms were similar. it was therefore concluded that fh1 represents a new strain within the species t. thermosaccharolyticum. the optimal growth temperatu ... | 2001 | 12483618 |
| thermoanaerobacterium thermosulfurigenes cyclodextrin glycosyltransferase. | cyclodextrin glycosyltransferase (cgtase) uses an alpha-retaining double displacement mechanism to catalyze three distinct transglycosylation reactions. to investigate these reactions as catalyzed by the cgtase from thermoanaerobacterium thermosulfurigenes the enzyme was overproduced (8 mg.l(-1) culture) using bacillus subtilis as a host. detailed analysis revealed that the three reactions proceed via different kinetic mechanisms. the cyclization reaction (cyclodextrin formation from starch) is ... | 2003 | 12492486 |
| glucoamylase from thermoanaerobacterium thermosaccharolyticum: sequence studies and analysis of the macromolecular architecture of the enzyme. | a chromosomal dna fragment with a length of 2,025 bp, carrying the structural gene coding for glucoamylase in thermoanaerobacterium thermosaccharolyticum, was cloned and sequenced. it coded for 695 amino acids, representing a polypeptide with a predicted molecular mass of 77.5 kda. the deduced amino acid sequence exhibited high homologies with the glucoamylase sequence of another bacterial glucoamylase (clostridium sp. g0005) and with fungal glucoamylases. the catalytic domain (amino acids 271 t ... | 1998 | 12501412 |
| crystal structure and evolution of a prokaryotic glucoamylase. | the first crystal structures of a two-domain, prokaryotic glucoamylase were determined to high resolution from the clostridial species thermoanaerobacterium thermosaccharolyticum with and without acarbose. the n-terminal domain has 18 antiparallel strands arranged in beta-sheets of a super-beta-sandwich. the c-terminal domain is an (alpha/alpha)(6) barrel, lacking the peripheral subdomain of eukaryotic glucoamylases. interdomain contacts are common to all prokaryotic family gh15 proteins. domain ... | 2003 | 12614608 |
| purification, characterization, and molecular cloning of a novel keratan sulfate hydrolase, endo-beta-n-acetylglucosaminidase, from bacillus circulans. | keratan sulfate (ks) is degraded by various enzymes including endo-beta-galactosidase, keratanase, and keratanase ii, which are used for the structural analysis of ks. we purified a novel ks hydrolase, endo-beta-n-acetylglucosaminidase, from the cell pellet and conditioned medium of bacillus circulans, by sequential chromatography using de52 and phenyl-sepharose columns with approximately 63- and 180-fold purity and 58 and 12.5% recovery, respectively. like keratanase ii of bacillus sp. ks36, th ... | 2003 | 12732618 |
| thermophilic h2 production from a cellulose-containing wastewater. | cellulose in wastewater was converted into h2 by a mixed culture in batch experiments at 55 degrees c with various wastewaters ph (5.5-8.5) and cellulose concentrations (10-40 g l(-1)). at the optimal ph of 6.5, the maximum h2 yield was 102 ml g(-1) cellulose and the maximum production rate was 287 ml d(-1) for each gram of volatile suspended solids (vss). analysis of 16s rdna sequences showed that the cellulose-degrading mixed culture was composed of microbes closely affiliated to genus thermoa ... | 2003 | 12882554 |
| biohydrogen production from starch in wastewater under thermophilic condition. | batch experiments were conducted to convert starch in wastewater into hydrogen at 55 degrees c at various wastewater ph (4.0-9.0) and starch concentrations (9.2-36.6 g/l). the maximum hydrogen yield of 92 ml/g of starch added (17% of the theoretical value) was found at wastewater ph 6.0, and the maximum specific hydrogen production rate of 365 ml/(g-vss.d) was at wastewater ph 7.0. the methane-free biogas contained up to 60% of hydrogen. the mixed liquor was composed mostly of acetate (40.2-53.4 ... | 2003 | 14550657 |
| crystal structure of beta-d-xylosidase from thermoanaerobacterium saccharolyticum, a family 39 glycoside hydrolase. | 1,4-beta-d-xylan is the major component of plant cell-wall hemicelluloses. beta-d-xylosidases are involved in the breakdown of xylans into xylose and belong to families 3, 39, 43, 52, and 54 of glycoside hydrolases. here, we report the first crystal structure of a member of family 39 glycoside hydrolase, i.e. beta-d-xylosidase from thermoanaerobacterium saccharolyticum strain b6a-ri. this study also represents the first structure of any beta-xylosidase of the above five glycoside hydrolase famil ... | 2004 | 14659747 |
| improved thermostability of bacillus circulans cyclodextrin glycosyltransferase by the introduction of a salt bridge. | cyclodextrin glycosyltransferase (cgtase) catalyzes the formation of cyclodextrins from starch. among the cgtases with known three-dimensional structure, thermoanaerobacterium thermosulfurigenes cgtase has the highest thermostability. by replacing amino acid residues in the b-domain of bacillus circulans cgtase with those from t. thermosulfurigenes cgtase, we identified a b. circulans cgtase mutant (with n188d and k192r mutations), with a strongly increased activity half-life at 60 degrees c. as ... | 2004 | 14705029 |
| characterization and development of two reporter gene systems for clostridium acetobutylicum. | the use of lacz from thermoanaerobacterium thermosulfurigenes (encoding beta-galactosidase) and lucb from photinus pyralis (encoding luciferase) as reporter genes in clostridium acetobutylicum was analyzed with promoters of genes required for solventogenesis and acidogenesis. both systems proved to be well suited and allowed the detection of differences in promoter strength at least up to 100-fold. the luciferase assay could be performed much faster and comes close to online measurement. reseque ... | 2004 | 14766557 |
| cloning of l-lactate dehydrogenase and elimination of lactic acid production via gene knockout in thermoanaerobacterium saccharolyticum jw/sl-ys485. | the gene encoding l-lactate dehydrogenase from thermoanaerobacterium saccharolyticum jw/sl-ys485 was cloned, sequenced, and used to obtain an l-ldh deletion mutant strain (td1) following a site-specific double-crossover event as confirmed by pcr and southern blot. growth rates and final cell densities were similar for strain td1 and the wild-type grown on glucose and xylose. lactic acid was below the limit of detection (0.3 mm) for strain td1 on both glucose and xylose at all times tested, but w ... | 2004 | 15007569 |
| the bacterial cytoskeleton and its putative role in membrane vesicle formation observed in a gram-positive bacterium producing starch-degrading enzymes. | bacteria may possess various kinds of cytoskeleton. in general, bacterial cytoskeletons may play a role in the control and preservation of the cell shape. such functions become especially evident when the bacteria do not possess a true wall and are nevertheless elongated (e.g. mycoplasma spp.) or under extreme cultivation conditions whereby loss of the entire bacterial cell wall takes place. bacterial cytoskeletons may control and preserve the cell shape only if a number of preconditions are ful ... | 2003 | 15153765 |
| cofactor-dependent enzyme catalysis in functionalized ionic solvents. | functionalized, hydrogen-bonding ionic liquids have been successfully evaluated as media for the performance of cofactor-dependent enzyme catalysed oxidations; the effects of incorporating hydroxyl groups into both the cation and anion have been studied and the dependence of activity upon water content has been evaluated. | 2004 | 15543284 |
| mahella australiensis gen. nov., sp. nov., a moderately thermophilic anaerobic bacterium isolated from an australian oil well. | a novel gram-positive, anaerobic and moderately thermophilic bacterium, strain 50-1 bon(t), was isolated from an australian terrestrial oil reservoir. cells were spore-forming straight rods, motile by peritrichous flagella. the optimum growth conditions were 50 degrees c, ph 7.5 and 0.1 % nacl. strain 50-1 bon(t) fermented arabinose, cellobiose, fructose, galactose, glucose, mannose, sucrose, xylose and yeast extract. glucose was fermented mainly into lactate, formate, hydrogen and co(2). the ma ... | 2004 | 15545453 |
| comparison of pressure and heat resistance of clostridium botulinum and other endospores in mashed carrots. | inactivation of bacterial endospores in food requires a combination of pressure and moderate heat. endospore resistance of seven clostridium botulinum strains was compared with those of bacillus spp. (b. cereus, b. subtilis, b. licheniformis, b. smithii, b. amyloliquefaciens) and thermoanaerobacterium thermosaccharolyticum with respect to pressure (600 to 800 mpa) and temperature (80 to 116 degrees c) treatments in mashed carrots. a large variation was observed in the pressure resistance of c. b ... | 2004 | 15553637 |
| conversion of food waste into hydrogen by thermophilic acidogenesis. | conversion of food waste into hydrogen by thermophilic acidogenesis was investigated as a function of organic loading rate (olr), hydraulic retention time (hrt) and ph in a continuous stirred tank reactor. in order to identify hydrogen-producing microorganisms, denaturing gradient gel electrophoresis (dgge) of the polymerase chain reaction (pcr)--amplified v3 region of 16s rdna analysis was conducted at each tested ph. the conversion of food waste into hydrogen was strongly influenced by the ope ... | 2005 | 15727153 |
| polyamine analysis for chemotaxonomy of thermophilic eubacteria: polyamine distribution profiles within the orders aquificales, thermotogales, thermodesulfobacteriales, thermales, thermoanaerobacteriales, clostridiales and bacillales. | cellular polyamines of 45 thermophilic and 8 related mesophilic eubacteria were investigated by hplc and gc analyses for the thermophilic and chemotaxonomic significance of polyamine distribution profiles. spermidine and a quaternary branched penta-amine, n4-bis(aminopropyl)norspermidine, were the major polyamine in thermocrinis, hydrogenobacter, hydrogenobaculum, aquifex, persephonella, sulfurihydrogenibium, hydrogenothermus, balnearium and thermovibrio, located in the order aquificales. thermo ... | 2004 | 15747232 |
| influence of divalent cations on the structural thermostability and thermal inactivation kinetics of class ii xylose isomerases. | the effects of divalent metal cations on structural thermostability and the inactivation kinetics of homologous class ii d-xylose isomerases (xi; ec 5.3.1.5) from mesophilic (escherichia coli and bacillus licheniformis), thermophilic (thermoanaerobacterium thermosulfurigenes), and hyperthermophilic (thermotoga neapolitana) bacteria were examined. unlike the three less thermophilic xis that were substantially structurally stabilized in the presence of co2+ or mn2+ (and mg2+ to a lesser extent), t ... | 2005 | 15752361 |
| a homology model for human alpha-l-iduronidase: insights into human disease. | genotype-phenotype correlations in genetic diseases for which missense mutations lead to disease remain a challenge. this is particularly true for diseases caused by alterations of proteins for which no three-dimensional structure is available. one such disease is mucopolysaccharidosis type i, a disorder arising from a lack of activity of the lysosomal enzyme alpha-l-iduronidase (idua, ec 3.2.1.76). this deficiency compromises the degradation pathway of glycosaminoglycans such as heparan sulfate ... | 2005 | 15862278 |
| cultivated anaerobic acidophilic/acidotolerant thermophiles from terrestrial and deep-sea hydrothermal habitats. | metabolic and phylogenetic diversity of cultivated anaerobic microorganisms from acidic continental hot springs and deep-sea hydrothermal vents was studied by molecular and microbiological methods. anaerobic organotrophic enrichment cultures growing at ph 3.5-4.0 and 60 or 85 degrees c with organic energy sources were obtained from samples of acidic hot springs of kamchatka peninsula (pauzhetka, moutnovski volcano, uzon caldera) and kunashir island (south kurils) as well as from the samples of c ... | 2005 | 15970992 |
| biofilm microbial community of a thermophilic trickling biofilter used for continuous biohydrogen production. | molecular methods were employed to investigate the microbial community of a biofilm obtained from a thermophilic trickling biofilter reactor (tbr) that was operated long-term to produce h(2). biomass concentration in the tbr gradually decreased as reactor bed height increased. despite this difference in biomass concentration, samples from the bottom and middle of the tbr bed revealed similar microbial populations as determined by pcr-dgge analysis of 16s rrna genes. nucleotide sequences of most ... | 2005 | 16006066 |
| occurrence and molecular characterization of cultivable mesophilic and thermophilic obligate anaerobic bacteria isolated from paper mills. | the aim of this work was to characterize the cultivable obligate anaerobic bacterial population in paper mill environments. a total of 177 anaerobically grown bacterial isolates were screened for aerotolerance, from which 67 obligate anaerobes were characterized by automated ribotyping and 41 were further identified by partial 16s rdna sequencing. the mesophilic isolates indicated 11 different taxa (species) within the genus clostridium and the thermophilic isolates four taxa within the genus th ... | 2005 | 16104353 |
| thermoglobin, oxygen-avid hemoglobin in a bacterial hyperthermophile. | the hemoglobin family of proteins, ubiquitous in all domains of life, evolved from an ancestral protein of primordial function to extant hemoglobins that perform a myriad of functions with diverged biochemical properties. study of homologs in bacterial hyperthermophiles may shed light on both mechanisms of adaptation to extreme conditions and the nature of the ancestral protein. a hemoglobin was identified in aquifex aeolicus, cloned, recombinantly expressed, purified, and characterized. this he ... | 2005 | 16135523 |
| enzyme-coupled assay for beta-xylosidase hydrolysis of natural substrates. | we describe here a new enzyme-coupled assay for the quantitation of d-xylose using readily available enzymes that allows kinetic evaluation of hemicellulolytic enzymes using natural xylooligosaccharide substrates. hydrogen peroxide is generated as an intermediary analyte, which allows flexibility in the choice of the chromophore or fluorophore used as the final reporter. thus, we present d-xylose quantitation results for solution-phase assays performed with both the fluorescent reporter resorufi ... | 2005 | 16151120 |
| characterization of a microorganism isolated from the effluent of hydrogen fermentation by microflora. | the hydrogen production yield from glucose by an isolate was investigated and compared to that by microflora. the isolate, thermoanaerobacterium thermosaccharolyticum ku001, from the microflora demonstrated approximately 2.4 mol/mol-glucose of hydrogen production with acetate/butyrate formation in an artificial medium. the fermentation pattern was similar to that observed for the hydrogen fermentation of wastewater by the microflora. a pcr-dgge analysis of the bacterial 16s rdna detected t. ther ... | 2001 | 16233118 |
| role of spontaneous current oscillations during high-efficiency electrotransformation of thermophilic anaerobes. | current oscillations at about 24 mhz were observed during electrotransformation (et) of the thermophilic anaerobes clostridium thermocellum atcc 27405, c. thermocellum dsm 1313, and thermoanaerobacterium saccharolyticum ys 485, using a pulse gated by a square signal generated by a custom generator. in experiments in which only the field strength was varied, all three of these strains resulted in a one-to-one correspondence between the appearance of current oscillations and successful et. oscilla ... | 2005 | 16332787 |
| regulation and characterization of xylanolytic enzymes of thermoanaerobacterium saccharolyticum b6a-ri. | during growth on xylan and xylose thermoanaerobacterium saccharolyticum b6a-ri produced endoxylanase, beta-xylosidase, arabinofuranosidase, and acetyl esterase, and the first three activities appeared to be produced coordinately. during nonlimiting growth on xylan, these enzyme activities were predominantly cell associated; however, during growth on limiting concentrations of xylan, the majority of endoxylanase activity was extracellular rather than cell associated. endoxylanase, beta-xylosidase ... | 1993 | 16348890 |
| a molecular basis for no selectivity in soluble guanylate cyclase. | soluble guanylate cyclases (sgcs) function as heme sensors that selectively bind nitric oxide (no), triggering reactions essential to animal physiology. recent discoveries place sgcs in the h-nox family (heme nitric oxide/oxygen-binding domain), which includes bacterial proteins from aerobic and anaerobic organisms. some h-nox proteins tightly bind oxygen (o2), whereas others show no measurable affinity for o2, providing the basis for selective no signaling in aerobic cells. using a series of wi ... | 2005 | 16407994 |
| mutagenesis of conserved charged amino acids in slh domains of thermoanaerobacterium thermosulfurigenes em1 affects attachment to cell wall sacculi. | slh domains (for surface layer homology) are involved in the attachment of proteins to bacterial cell walls. the data presented here assign the conserved trae motif within slh domains a key role for the binding. the charged amino acids arginine (r) or/and glutamic acid (e) were replaced via site-directed mutagenesis by different amino acids. effects were visualized in an in vitro binding assay using native cell wall sacculi of thermoanaerobacterium thermosulfurigenes em1 and different variants o ... | 2006 | 16470371 |
| purification and characterization of the (alpha)-glucuronidase from thermoanaerobacterium sp. strain jw/sl-ys485, an important enzyme for the utilization of substituted xylans. | a cell-associated (alpha)-glucuronidase was purified to gel electrophoretic homogeneity from the thermophilic anaerobic bacterium thermoanaerobacterium sp. strain jw/sl-ys485. this enzyme had a pi of 4.65, a molecular weight of 130,000, and two subunits; the molecular weight of each subunit was 74,000. the enzyme exhibited the highest level of activity at ph 5.4 and 60(deg)c, as determined by a 5-min assay. the k(infm) and k(infcat) values of the enzyme for 4-methylglucuronosyl xylobiose were 0. ... | 1995 | 16534958 |
| a high-molecular-weight, cell-associated xylanase isolated from exponentially growing thermoanaerobacterium sp. strain jw/sl-ys485. | an unusual cell-associated (beta)-1,4-xylanase was purified to gel electrophoretic homogeneity from a cell extract of the bacterium thermoanaerobacterium sp. strain jw/sl-ys485 harvested at the late exponential growth phase. the molecular mass of the xylanase was 350 kda as determined by gel filtration and 234 kda as determined by native gradient gel electrophoresis. the enzyme contained 6% carbohydrates. heterosubunits of 180 and 24 kda were observed for the xylanase on sodium dodecyl sulfate-p ... | 1995 | 16534977 |
| reclassification of thermoanaerobium acetigenum as caldicellulosiruptor acetigenus comb. nov. and emendation of the genus description. | although the type species of the genus thermoanaerobium, thermoanaerobium brockii, was transferred to thermoanaerobacter, thermoanaerobium acetigenum was not transferred. therefore, thermoanaerobium acetigenum should be reclassified. based on 16s rrna gene sequence analysis and re-examination of physiological properties of the type strain, x6b(t) (=dsm 7040(t) = atcc baa-1149(t)), we propose that thermoanaerobium acetigenum should be reclassified as caldicellulosiruptor acetigenus comb. nov. str ... | 2006 | 16738119 |
| changes in bacterial community during fermentative hydrogen and acid production from organic waste by thermophilic anaerobic microflora. | changes in fermentation pattern during the treatment of organic wastes containing solid materials by thermophilic anaerobic microflora were investigated with respect to product formation and bacterial community structure during hydrogen production. | 2006 | 16882140 |
| identification of mesophilic and thermophilic fermentative species in anaerobic granular sludge. | large quantities of biodegradable food waste in the form of fruit and vegetables are still being deposited in landfill sites in ireland. the development of an anaerobic digestion process using fermentative species which degrade the carbohydrate-rich waste could divert the food waste from landfills. we identified fermentative species grown on glucose and sucrose at mesophilic and thermophilic temperatures using molecular biology techniques. the dominating fermentative bacteria of the mesophilic s ... | 2006 | 16939079 |
| cytoskeletal elements in bacteria mycoplasma pneumoniae, thermoanaerobacterium sp., and escherichia coli as revealed by electron microscopy. | recently, electron microscopic studies on the eubacteria mycoplasma pneumoniae, thermoanaerobacterium sp., and escherichia coli have revealed the existence of cytoskeletal elements so far unknown in prokaryotes. the wall-less bacterium m. pneumoniae contains, in close vicinity to the inner face of the cytoplasmic membrane, a helically organized lining composed of protein elements that form a regular network of meshes that encloses the entire cytoplasm. numerous regularly spaced pin-like structur ... | 2006 | 16983198 |
| inactivation kinetics of selected aerobic and anaerobic bacterial spores by pressure-assisted thermal processing. | the combined pressure-thermal inactivation kinetics of spores from three strains of anaerobic (clostridium sporogenes, c. tyrobutylicum, and thermoanaerobacterium thermosaccharolyticum), and six strains of aerobic (bacillus amyloliquefaciens and b. sphaericus) bacteria were studied. spores of these bacteria were prepared in deionized water and treated in a custom-made kinetic tester over various pressure (0.1 and 700 mpa) and thermal (105 and 121 degrees c) combinations. survivor data were model ... | 2007 | 17196696 |
| thermoanaerobacterium aciditolerans sp. nov., a moderate thermoacidophile from a kamchatka hot spring. | an anaerobic, moderately thermoacidophilic bacterium, strain 761-119t, was isolated from an acidic hot spring in the orange field of the uzon caldera (kamchatka, far-eastern russia). cells were spore-forming, gram-positive rods, possessing one polar flagellum. growth of strain 761-119t was observed between 37 and 68 degrees c and in the ph(20 degrees c) range 3.2-7.1. no growth was observed within 5 days of incubation at or below 35 degrees c and at or above 70 degrees c, as well as at or below ... | 2007 | 17267961 |
| [the product specificity evolution of cyclodextrin glucanotransferase: problems and challenges]. | cyclodextrin glucanotransferase, the essential enzyme for the production of cyclodextrins, has become the focus of scientific research nowadays. although many related enzyme properties are well known, the crucial factors in product specificity determination remain to be answered. here, the recent research progresses of cyclodextrin glucanotransferase, especially those about the evolution of product specificity, were reviewed, and the scientific problems were discussed. | 2007 | 17460885 |
| an ability of isolated strains to efficiently cooperate in ethanolic fermentation of agricultural plant refuse under initially aerobic thermophilic conditions: oxygen deletion process appended to consolidated bioprocessing (cbp). | for bioconversion of bean curd refuse, a processing by-product of bean curd, ethanol-producing anaerobic thermophiles (strains kpu03 and kpu04) were newly isolated. both of them degraded hemicellulose, but not cellulose at all. phylogenetically, strains kpu03 and kpu04 belong to the clostridium and thermoanaerobacterium genus, respectively. aerobic thermophiles degrading cellulose were also isolated newly. among them, strain kpub3 particularly enhanced ethanol production by anaerobic strain kpu0 ... | 2008 | 17507216 |
| operation of a two-stage fermentation process producing hydrogen and methane from organic waste. | a pilot-scale experimental plant for the production of hydrogen and methane by a two-stage fermentation process was constructed and operated using a mixture of pulverized garbage and shredded paper wastes. thermophilic hydrogen fermentation was established at 60 degrees c in the first bioreactor by inoculating with seed microflora. following the hydrogenogenic process, methanogenesis in the second bioreactor was conducted at 55 degrees c using an internal recirculation packed-bed reactor (irpr). ... | 2007 | 17593750 |
| thermoanaerobacter sulfurigignens sp. nov., an anaerobic thermophilic bacterium that reduces 1 m thiosulfate to elemental sulfur and tolerates 90 mm sulfite. | two anaerobic thermophilic bacteria, designated strains jw/sl824 and jw/sl-nz826(t), were isolated from an acidic volcanic steam outlet on white island, new zealand. cells were rod-shaped, spore-forming, motile and gram-stain negative, but contained gram-type positive cell wall. strain jw/sl-nz826(t) utilized various carbohydrates including xylose and glucose. the fermentation end products produced from glucose in the absence of thiosulfate were lactate, ethanol, acetate, co(2) and h(2). the tem ... | 2007 | 17625170 |
| in situ analysis of sulfur species in sulfur globules produced from thiosulfate by thermoanaerobacter sulfurigignens and thermoanaerobacterium thermosulfurigenes. | the firmicutes thermoanaerobacter sulfurigignens and thermoanaerobacterium thermosulfurigenes convert thiosulfate, forming sulfur globules inside and outside cells. x-ray absorption near-edge structure analysis revealed that the sulfur consisted mainly of sulfur chains with organic end groups similar to sulfur formed in purple sulfur bacteria, suggesting the possibility that the process of sulfur globule formation by bacteria is an ancient feature. | 2007 | 17644590 |
| c-terminal effect of thermoanaerobacter tengcongensis ribosome recycling factor on its activity and conformation changes. | the in vivo activities and conformational changes of ribosome recycling factor from thermoanaerobacter tengcongensis (tterrf) with 12 successive c-terminal deletions were compared. the results showed that tterrf mutants lacking one to four amino acid residues are inactive, those lacking five to nine are reactivated to a similar or a little higher level than wild-type tterrf, and those lacking ten to twelve are inactivated again gradually. conformational studies indicated that only the ans bindin ... | 2007 | 17697668 |
| a cbs domain-containing pyrophosphatase of moorella thermoacetica is regulated by adenine nucleotides. | cbs (cystathionine beta-synthase) domains are found in proteins from all kingdoms of life, and point mutations in these domains are responsible for a variety of hereditary diseases in humans; however, the functions of cbs domains are not well understood. in the present study, we cloned, expressed in escherichia coli, and characterized a family ii ppase (inorganic pyrophosphatase) from moorella thermoacetica (mtcbs-ppase) that has a pair of tandem 60-amino-acid cbs domains within its n-terminal d ... | 2007 | 17714078 |
| community analysis of hydrogen-producing extreme thermophilic anaerobic microflora enriched from cow manure with five substrates. | the present study analyzed the community structures of anaerobic microflora producing hydrogen under extreme thermophilic conditions by two culture-independent methods: denaturing gradient gel electrophoresis (dgge) and clone library analyses. extreme thermophilic microflora (etm) was enriched from cow manure by repeated batch cultures at 75 degrees c, using a substrate of xylose, glucose, lactose, cellobiose, or soluble starch, and produced hydrogen at yields of 0.56, 2.65, 2.17, 2.68, and 1.73 ... | 2007 | 17828395 |